Valve for pneumatic tools



J. M. CROWE VALVE FOR vPNEUMATIG TOOLS Filed Mar. 22, 1919 l J ,00x

lllllllm L? @en for f kf-2401725 Felle. 27, i923.

PATENT SOHN lViES-IALL CROVJE, 0F COVINGTON, KENTUCKY, ASSIGNOR OF ONE-HALF TO LOUlS K. DE BUS, OF CINCINNATI, GH'IO.

VALVE FOR PNEUIATIC TOOLS.

Application led March 22, 1919.

To nl] volw/1a :it may con (fc/Wi Be it known that l, JOHN MARSHALL Csown, a citizen ofthe United States of .'tinierica, and a. resident of Covington, in the county of Kenton and titate of Kentucky, have invented a new and useful Improvement in Valves for Pneumatic Tools, of which the following is a specification.

My invention relates to a valve for use with a tool of the type described in United States patent to Ash, -,l95,89.7, which adzmted to he moved by hand to admit fluid unde pressure alternately to opposite ends of a -sten cylinder, to reciprocate the piston therein with greater force in one direction than in the other.

'The object of my invention is a valve which may be actuated quickly by a simple movement, which will not detract from the pressure of the fluid admitted at one end, and has a simple means for lowering the force of the fluid admitted to the other end of the cylinder.

rlhe object is attained by the means described in the specification, and illustrated in the accompanying drawing, in which;

Fig. l, is a front elevation of the head Ot a pneumatic tool provided with a valve embodying my invention.

Fig. 2, is a side elevation of the same.

Fig. 3, is a sectional view taken upon line 3-3 of Figure 2.

Fig. 4, is a sectional view taken upon line el--Ll of Figure l.

Figs. 5 and 6, are views similar to Figure lwith the valve in different positions.

Fig. 7 is a vertical section of the tool.

rlhe housing A., of my valve forms the head of a pneumatic tool and is screw threaded to litthe piston cylinder B, thereof. The housing has a. transverse tapered recess (l, and a longitudinal central bore eX- tencing through it, the outer portion (r1, of which receives the admission pipe C, and the lower portion (1,2, of which leads into the piston cylinder B. ln tools of this type the cylinder B has a port near its lower endras shown at in the Ash patent, which construction is common and old in the art, and therefore requires no illustration or further reference. Housing il, has likewise a transversebore, one end of which receives the pipe Serial No. 284,501.

C1, which connects with the end of the piston cylinder B, opposite the end in which the housing A is seated and the other end C2, of which constitutes an exhaust port.

Valve D, is tapered to fit the walls ol recess a, and has an enlarged diametrical bore (Z, a bore (Z, of reduced diameter and a peripheral groove (Z2, of reduced diameter and located upon the side of the bore (Z, oph posite the bore (l1. Valve D, has a stem (Z3, upon one end of which a handle E, is secured and the opposite end of which passes through cap nut F, and receives a pin (Z4, which is adapted to set in notches in the tension regulating block f. Between the cap nut F, and the valve D, and surrounding the valve stein is a coiled spring (Z5.

After the valve D, has been seated in its recess and the cap nut F, has been adjusted, the parts are secured in fixed relation hy passing a handle G, through the casing A, and in contact with a notch 7, in the cap nut F. The handle G, therefore performs a double function, that of holding the parts of the valve in their fixed relation, and of a handle by means of which the tool may be handled by the operator. Piston cylinder B may have near its lower ond,ports through which the air exhausts upon the forward movement of the piston. Such a port is shown at P, Fig. 7.

In operation by movement of the handle E, the operator brings the bore (Z, in alignment with the ends a, (t2, of the longitudinal bore in the housing A, as shown in Fig. 6, the fluid under pressure then has a direct and unimpeded passage to the piston cylinder and drives the piston therein with undiminished force to the opposite end of the cylinder. By a partial revolution of the handle E, the operator then moves the valve to a position wherein the reduced hore (I, registers with the admission port ci. and one end of the bore d, registers with pipe C (F ig. 5). This causes the groove d2, to place the passage (L2 in communication with the exhaust port C2. The reduced size of the bore (l, and the tortuous passage through which the Huid under pressure has to pass reduces the force of the uid under pressure which is admitted to the opposite end of the psiton cylinder. The reduced size of the groove di',

likewise7 impedes the escape of fluid from the piston cylinder, that the piston is returned to the upper end of the piston cylinder with much less force than that with which it was carried on its forward stroke.

The movement olf the handle E., to put the opposite ends of the cylinder in communication with the fluid under pressure is through a small arc o' a circle as is shown in Figs. 5 and 6. Hence this movement is one which an operator can make with great rapidity. rl`liis is advantageous in that it permits the operator to deliver several blows of the pis ton in,a.second.

lhenvthe valve is moved to the position shown in Fig. 6, the port in ythe cylinder Wall, such as the port in the cylinder shown by patentee .sh7 permits the cylinder helov.7 the piston to exhaust on the power stroke ol the piston and permits the iluiijl under pressure to escape when the piston has' reached the end ot its pov-Jer or down stroke, and When the valve is moved to the position shown in 5 the air under oressure starts the piston. on its return or upstroke anifl moves the piston upward beyond such eert in the cylinderj whereupon part of the fluid under pressure entering the lovver part of the cylinder` escapes thru the port in the cylinder9 While part et the fluid under pressure cou'ipletes the return stroke.

Pin (Z4, limits the loue-.rd movement valve D, against the tension el? the spring ali"5V so that there is a space for the circulation ot oil which surrfuinds valve l? u'hichseats in its recess sutcientlysnugly to prevent the passage of air between it andthe Walls ot the recess. rllhe stem (Z39 jiournals at one end in casing` A. and at the oppositeend .in cap nut F. Thisconstruetiou takes the u/'ear oli ot the valvel)5 to a large extent. However should the valve become Worn allowance may be make tor the .vear by removing the pin d4, unscreiving the block ,f7 seep, and

passingy the pin t through the stern and having i t engage the next notch in the block j',

v's/Vhat l claim is l. A valve for a pneumatic tool comprish ing a housing having cess-1% 'a longitudinal bore and a transverse bore intercepted hy the and a valve seated in the recess and havin` an enlargedvdiauietrical here adapted to be alignment with the longitudinal le. in tlm. housing. a reduced here leadi fr into the C metrical if; re a" an :icute is` a ced peripheral groove upon its si e epposi reduced here a treusvorse .f'ulve Yn and a handle mounted upon if'alve stein.

2. valve. for a `one/lunatic tool compris ing' a housing` having' s tapered transit/Ierse 1 ve seated in the recess e valve stein ext-end- ;.e housing., u, @j one end ot the valve e onen enf t the recess. valve the cau.) nut i A, an adjustuoe bleek unen the valve stein tor regulat- 'ion of the val. tl

strilg orcssure Jhr ietoo i transverse recess i D Y ha f i i, eated inV the houeine..a.y canr nut closins the und a handle oas.. the housing' and engaginrgthe p nut and locking); it against n. I lu lfiestinfiony Where-o... have hereunto subscribed my this dav ot larch. l0. 1919.

JOHN MARSHALL GROWTH. 

